Power generation performance of a crystal solar battery module that uses a wafer made of silicon serving as a main material is improved by improvement in performance of a solar battery cell serving as a power generation element.
However, with improvement in efficiency of a cell, an electric current is increased and a resistance loss at a wiring member (an interconnector) that is mainly made of copper and connects cells to each other at the time of modularization is also increased. Accordingly, performance after modularization is not improved for an amount corresponding to an amount of the improvement in the performance of a cell, but is reduced for an amount of increase in the resistance loss at the interconnector.
As a remedy for this problem, there has been conventionally proposed a technique of reducing a resistance loss by increasing a cross-sectional area of an interconnector (see Patent Literature 1, for example).